Silicon MOSFETs have been sensitive to Total Ionizing Dose (TID) since the early days of radiation studies on electronic devices, and that is still the case after more than 40 years and 20 generations (nodes) of CMOS technologies. Silicon dioxide (SiO2), the insulator that has been a blessing for the semiconductor industry because of its compatibility with Si, has instead been a curse for the application of CMOS circuits in radiation environments. Defects in SiO2 and at its interface with the Si channel of MOS transistors have determined the TID response of CMOS circuits built in micrometer bulk planar technologies of the 1980s as well as in today’s nanometer-scale FinFETs.

In this course, prepared in collaboration with Dr. Giulio Borghello (CERN), and Dr. Stefano Bonaldo (DEI, University of Padova), Dr. Federico Faccio (CERN) will illustrate the basic mechanisms of TID in SiO2: charge yield, charge and hydrogen transport, charge trapping and de-trapping, interface state activation and annealing. The course will show how very similar mechanisms have differently affected the performance of MOSFETs in time. While in older technologies the gate oxide was the weak point and determined failure at krad TID levels, with the down-scaling of CMOS in the 100 nm range and below, the radiation response became dominated by auxiliary oxides like Shallow Trench Isolation (STI) or spacers.

The last part of the course will thus focus on the consequences of ionization in these insulators: the leakage currents that often represent the prevalent limitation to radiation tolerance in recent technologies, the dose-rate effects observable at high TID levels, and the transistor size dependencies including RINCE, RISCE (Radiation-Induced Narrow or Short Channel Effects) and halo implant effects. The manufacturing of these auxiliary oxides is less controlled and less uniform across nodes and fabrication plants than for the thermally grown gate oxide, leading to a wide variability in radiation response. This will be illustrated by a comparison between manufacturers, plants of the same manufacturer and manufacturing lots. In conclusion the course will show how, with or even without costly dedicated design techniques, TID tolerance to ultra- high levels (>100Mrad) is not a dream anymore.

Dr. Ani Khachatrian from the US Naval Research Laboratory will present an overview of single- event effects phenomena in devices and integrated circuits. In harsh radiation environment, in addition to total ionizing dose, displacement damage dose, microelectronic devices are susceptible to single-event effects. SEE is a phenomenon that occurs when single energetic particle such as alpha particle, heavy ion, proton, neutron or other highly energetic particle, strikes sensitive area of a microelectronic device. There are three steps that can lead to a single-event effect: charge generation via both direct and indirect interactions of an energetic particle with matter; charge collection and the associated modification of the electrical potential at a sensitive node; and the response of the circuit to the collected charge. Single-event effects can be either non-destructive or destructive and can disrupt the normal operation of a device leading to potential failure events. Non-destructive single-event effects can manifest as single-event upsets, single-event transient, multi-bit upsets, and upsets hard error. Single-event latchup, single-event burnout and single event gate rapture are the examples of destructive events. With continued technology scaling, microelectronic devices growing more complex and emergence of novel semiconductor materials, the understanding of the mechanisms leading to single-event effects becomes increasingly important.

The presentation will discuss mechanisms responsible for single-event effects formation in devices and integrated circuits; types of single-event effects in analog, digital, logic circuits, memory cells and modern microelectronic devices and different test methods of single-event effects in modern technologies, their benefits and limitations.

Photonics is an important topic due to its wide-ranging applications and transformative impact on various fields, from communications, data transfer, imaging and sensing. Today, high performance photonic solutions developed for terrestrial applications are more and more implemented in radiation-rich environments. It is then crucial to study the radiation effects on these technologies in order to be able to assess their vulnerabilities and if needed to apply hardening techniques before integrating them under irradiation.

In this lecture Prof. Sylvain Girard from University of Saint-Etienne and Dr. Cedric Virmontois from CNES will describe radiation effects on two of the main photonic technologies: image sensors and optical fibers.

The first part will address radiation effects on silica-based optical fibers and bulk glasses. The advantages and limitations for the implementation of these technologies in various harsh environments will be discussed as well as the different targeted applications from communications to sensors. The parameters governing their macroscopic radiation responses through the generation of radiation induced point defects will be reviewed as well as the existing strategies to design radiation hardened optical fibers and fiber sensors.

The second part will address image sensors and detectors. A particular emphasis will
be made on visible and infrared technologies used in space. After a description of the device principles, the lecture will focus on the performances degraded by radiation. Dark signal, noises, charge transfer inefficiency, quantum efficiency and blinking pixels will be introduced as well as how these parameters evolve under irradiation.